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Saturday, 19 of February of 2005



Tsunamis can occur in Brazil?


Eduardo Frigoletto de Menezes

Before the final occurred tragedy of December of 2004, the word tsunami was practically unknown of the Brazilians and good part of the other peoples of occident.


The junction of the words "tsu" that it means "port" and "nami" that means "wave, sea" results in the expression created for the Japanese that is accustomed to suffer with land tremors, tidal waves, hurricanes etc.


How much to its sprouting, the theory says that the continents are on twelve gigantic plates that in turn are floating on melted rocks (magma). In the measure where a plate if moves away from the other, it comes close itself to one third. When she has the shock between plates occur the land tremors. When this occurs in the deep one of the oceans, the result is the tsunamis.


In August of 1883, one tsunami with approximately 35 meters of height reached the Pacific Ocean after the entrance in eruption and posterior landslide of Krakatoa volcano. To have an idea, this is the height of a building of 10 floors.


In case that a wave of this magnitude reached the alagoan coast, simply it would destroyed the quarters of the part low of Maceió (Jatiúca, Pajuçara, Green Tip, Jaraguá, Trapiche of the Bar etc) and the too much littoral cities as for example: Bar of Saint Miguel, Maragogi, Paripueira and Bar of Saint Antonio.


Tsunami that it reached recently Asia reached 9º in Scale Richter, being 5º bigger land tremor since the year of 1900, about 10 meters of height, incredible 1000 kilometers of the 800 for the moment extension and traveled km. The energy produced for the phenomenon made with that islands "walked" about 20 meters, the line of the equator if it reduced in one millimeter, shortened the duration of the day in 3 thousandth of second besides having dislocated the imaginary axle of rotation of the Land in six centimeters.


The deceased number is esteem in 300.000. The phenomenon occurred for the shock of two tectonics plates - the Australian and of the Eurasian and, only in Indonesia, about 1.100 bodies is found per day in rubbles and, many deceased never will be found.


In this in case that, what more flame the attention is the social exclusion that increased the deceased number very. It would be enough to a detection system and alarm so that thousands of lives had been salutes. In Taiwan, a tremor occurred in 1999 and that it reached 7.9º in Scale Richter caused more than 2,000 deaths little, which had to the adopted norms of anti-seismic construction in that country. In the Maldivas Islands a wall in the sea was constructed to minimize the action of the great waves. It is a nonsense that after the recent tragedy only is that it is said in adopting writ of prevention.


But after all of accounts, and in Brazil they can or not occur tsunamis?


For our luck, Brazil is to the center of the South American Plate that is if moving away from the African Plate. Being thus, the hypothesis of shock between the plates is discarded. However the real danger comes of the archipelago of situated the Canaries Islands in the coast occidental person of Africa where in the La island Palm volcano Cumbre Vieja exists that if to enter in eruption can pour up to 500 land km what a great wave would cause a strong impact in the Atlantic Ocean having formed. This wave, would strong come in direction to America reaching northeast part of Brazil, America Central and North America.


In the Brazilian case, the reached states more would be that situated between the Great River of the North and Amapá and Alagoas hardly would be affected.


Another remote possibility is the one formation tsunami for the impact of the fall of an asteroid in the ocean, as the one that would have reached Mexico has about 65 million years with 1000 meters of height. This wave is made responsible by some scholars for the extinguishing of good part of the life in the planet, also of the dinosaurs.


It is better to relax and to twist so that God is exactly Brazilian!



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